The effectiveness of mobile app-based interventions in facilitating behaviour change towards healthier and more sustainable diets: a systematic review and meta-analysis.

backgroundDigital health apps have been shown to influence healthy eating, but whether they can promote environmentally friendly diets remains unclear. In countries where diets typically contain a high proportion of carbon-intensive foods (e.g., meat), transitioning to healthier alternatives (e.g., fruit, vegetables, and legumes) can substantially reduce food-related greenhouse gas emissions while also improving public health. Our systematic review and meta-analysis aimed to investigate the effectiveness of mobile apps in facilitating more sustainable and healthier diets among adults from high-income countries.

methodsWe searched MEDLINE, EMBASE, PsycINFO, CINAHL, Global Health, GreenFILE, Web of Science, Cochrane Trials, and ClinicalTrials.gov from inception until Jan 20, 2025. We included studies that reported the effects of app-based behavioural interventions on the consumption of fruit, vegetables, legumes, nuts, fish, dairy, and/or meat, compared to a control, baseline period, or different intervention. For outcomes measured in at least two studies, we conducted random effects meta-analysis and meta-regression to understand population differences and the role of specific intervention components.

resultsOf the 7356 records screened, 21 were included. Nine studies scored ‘high’, 10 scored ‘fair’, and two scored ‘low’ for reporting transparency. Combined, the studies analysed 12,898 participants, interventions lasted from three days to six months, and outcomes were assessed up to 12 months post-intervention. Forty percent of studies targeted populations with at least one health risk factor and 81% of study populations did not meet dietary guidelines at baseline for their primary outcome. Meta-analyses indicated that app use led to increased fruit and vegetable consumption (0.48 portions/day, 95% CI 0.18, 0.78, p = 0.002) and a small decrease in meat consumption (-0.10 portions/day, 95% CI -0.16, -0.03, p = 0.004), with meat-focussed apps showing as more effective than general apps for meat reduction. Meta-regression also revealed that message-based content was particularly effective in promoting meat reduction. There were no pronounced effects on legume or dairy consumption, or differences across populations.

conclusionOur results indicate that apps could be a valuable addition to the multiple interventions required to promote sustainable diets. However, to strengthen the evidence for outcomes beyond fruit and vegetables, we need standardised reporting of populations and intervention components.